The present invention relates to steering wheel molds that are employed to integrally mold covers and pads of steering wheels.
A typical steering wheel is constituted by a metal core and a cover, which is made of urethane foam or the like and which covers the core.
As shown in FIG. 23, in the prior art, a metal core 11 includes a boss plate 12 and spoke cores 13A, 13B, 13C, which are formed by die casting aluminum. The ends of the boss plate 12 are embedded in the spoke cores 13B, 13C to connect the boss plate 12 with the spoke cores 13B, 13C.
A boss 14 is provided by welding a boss body 15 to the boss plate 12. To embed the boss plate 12, the boss 14 and a wheel core 16, which is formed separately from the boss 14, are arranged in a mold (not shown).
Molten aluminum is then charged into a cavity defined in the mold. The spoke cores 13A-13C, boss connectors 21, spoke connectors 22, and a supporter core 24 are formed when the aluminum cools and hardens. The supporter core 24 is connected to the boss plate 12 by two reinforcing bars 25. The spoke cores 13B, 13C are connected to the spoke core 13A by the spoke connectors 22.
This structure securely connects the spoke cores 13A-13C, the wheel core 16, and the boss 14 to one another. Furthermore, a relatively large opening 23 is defined between the boss 14, the boss connectors 21, and the spoke connectors 22.
As shown in FIG. 25, a steering wheel W includes a gripping wheel 81, which is formed by covering the wheel core 16 with a cover, and spokes 82, which are formed by covering each spoke core 13A-13C with a cover. The gripping wheel 81 and the spokes 82 constitute a wheel body 84. A space is provided between the spokes 82 and the reinforcing bars 25 to accommodate an air bag device. The space is closed by a pad 85.
In the above prior art steering wheel W, the pad 85, and the wheel body 84 are formed separately. This increases the number of manufacturing steps and increases costs. In addition, the pad 85 and the wheel body 84 each require a different mold. This further increases costs.
To mold the pad 85 integrally with the wheel body 84, a pad mold must be arranged adjacent to the place where the pad 85 is located. However, the arrangement of a pad mold would be hindered by the boss plate 12, which is opposed to the pad 85, the supporter core 24, and the reinforcing bar 25. Furthermore, a pad mold would obstruct the opening and closing of the molds used to mold the wheel body 84. Thus, despite the additional costs, it has heretofore been necessary to form the pad 85 and the wheel body 84 separately.